Data from: Essential gene disruptions reveal complex relationships between phenotypic robustness, pleiotropy, and fitness

The concept of robustness in biology has gained much attention recently, but a mechanistic understanding of how genetic networks regulate phenotypic variation has remained elusive. One approach to understand the genetic architecture of variability has been to analyze dispensable gene deletions in model organisms; however, the most important genes cannot be deleted. Here, we have utilized two systems in yeast whereby essential genes have been altered to reduce expression. Using high‐throughput microscopy and image analysis, we have characterized a large number of morphological phenotypes, and their associated variation, for the majority of essential genes in yeast. Our results indicate that phenotypic robustness is more highly dependent upon the expression of essential genes than on the presence of dispensable genes. Morphological robustness appears to be a general property of a genotype that is closely related to pleiotropy. While the fitness profile across a range of expression levels is idiosyncratic to each gene, the global pattern indicates that there is a window in which phenotypic variation can be released before fitness effects are observable.近年来，生物学中的稳健性（robustness）概念受到广泛关注，但学界对遗传网络如何调控表型变异的机制性理解仍不明晰。解析变异遗传结构的一种经典方法，是对模式生物中的可缺失基因开展敲除分析；然而，多数至关重要的必需基因（essential gene）无法被敲除。本研究在酵母中构建了两套系统，通过改造必需基因以降低其表达水平。借助高通量显微镜成像与图像分析技术，我们对酵母中绝大多数必需基因的大量形态表型及其相关变异进行了系统表征。研究结果显示，表型稳健性对必需基因表达水平的依赖程度，远高于其对可缺失基因存在与否的依赖。形态稳健性似乎是基因型的一种通用属性，且与基因多效性（pleiotropy）紧密相关。尽管不同表达水平下的适合度特征因基因而异，但其全局模式表明，在可观测到适合度影响之前，存在一个可释放表型变异的表达窗口。